feat(mining-slot): derive GRANDPA voters from recent mining activity

[blakebyrnes]

Rotate GRANDPA authorities every 240 blocks using recently active mining operators, with a 3-rotation activity window and 2x liveness fallback window.

Normalize to a fixed 10,000 vote budget, enforce a 15% max per-authority share when feasible, and fall back to equal weighting below the 7-authority minimum needed to enforce that bound.

Also add node-side single-local-GRANDPA-key guards at startup and runtime to reduce accidental double-vote misconfiguration.

[blakebyrnes]

@copilot can you review this before i mark public?

[Copilot]

@blakebyrnes I've opened a new pull request, #418, to work on those changes. Once the pull request is ready, I'll request review from you.

[Copilot]

Pull request overview

Implements GRANDPA authority rotation driven by recent mining-slot activity, with vote-weight normalization and concentration caps, plus node-side safeguards to prevent misconfigured multiple local GRANDPA keys.

Changes:

• Add mining-activity-based GRANDPA authority derivation (recency window + fallback window, normalization to a fixed vote budget, max-share guard, max authority count).
• Wire the derivation into Argon/Canary runtimes’ GRANDPA rotation hook and add comprehensive pallet tests + mock config constants.
• Add node startup/runtime guard to refuse (and detect) multiple local GRANDPA keys; update miner-running documentation on bid-close timing.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
runtime/common/src/config.rs	Adjust rotation cadence and introduce new GRANDPA derivation configuration constants.
runtime/canary/src/lib.rs	Use derived authorities for scheduled GRANDPA changes; plumb new mining-slot config associated types.
runtime/argon/src/lib.rs	Same as Canary: derive and schedule authority changes; plumb config types.
pallets/mining_slot/src/lib.rs	Expose new grandpa module and document the derivation policy in pallet docs; extend Config trait.
pallets/mining_slot/src/grandpa.rs	New implementation for deriving GRANDPA authorities from recent mining activity and allocating weights.
pallets/mining_slot/src/mock.rs	Add mock parameter_types for new GRANDPA derivation config hooks.
pallets/mining_slot/src/tests.rs	Add targeted unit tests covering eligibility, window boundaries, determinism, caps, and invariants.
node/src/service.rs	Add keystore guards to ensure a single local GRANDPA key at startup and during runtime.
docs/run-a-miner.md	Update bid-close timing documentation (200 → 30 ticks).

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[Copilot]

Pull request overview

Copilot reviewed 10 out of 10 changed files in this pull request and generated 4 comments.

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